A CPLD is a digital integrated circuit for constructing a logical function according to a user requirement, and is widely applied in various devices, such as a board. With an increasingly higher requirement for reliability and security of a device, if a problem occurs when the CPLD runs, or a user requirement changes, a program of the CPLD needs to be upgraded. However, a pin of the CPLD is usually released after the program of the CPLD is upgraded, which may enable a pin signal of the CPLD to jump after the upgrade and therefore result in different statuses of a device on which the CPLD is located before and after the upgrade; consistency of the statuses before and after the upgrade needs to be ensured by means of resetting, thereby resulting in an interruption of a current service of the device. If the signal that jumps is a key signal, for example, a control signal that is of the device and is used to control functions of some service processing modules on the device, services of the entire device may be affected.